The Graton Water Resource Recovery Facility (WRRF) in Sonoma County, Calif., is owned and operated by the Graton Community Service District (GCSD). GCSD was mandated in 2004 to upgrade its 1979 secondary aerated lagoon to tertiary discharge standards.
A chicken processing facility in central North Carolina generates a daily average of about 625 gal per minute (gpm) of wastewater from the various processes within the facility. The bulk of treated wastewater is discharged to a creek, while about 175 gpm is recycled for reuse within the facility. The treated wastewater is required to meet stringent discharge limits, which include a total suspended solids (TSS) limit of less than 20 parts per million (ppm).
The Roth Lane Wastewater Treatment Plant (WWTP) in Mechanicsburg, Pa., is owned and operated by Hampden Township Sewer Authority. The 4.82-million-gal-per-day WWTP was constructed in 1982 and upgraded in 2010 to meet the more stringent nutrient limits associated with Pennsylvania Commonwealth’s Chesapeake Bay Nutrient Reduction Strategy.
Municipal potable water applications for Schreiber’s Fuzzy Filter have grown during the past few years thanks to a strong relationship the company has established with Strand Associates, Inc., a consulting engineering firm that is active in the water industry. Schreiber currently has two systems successfully operating and a third system scheduled to start in July of 2012. All three systems process membrane backwash water for feeding back into the system, thereby improving the water plant’s overall efficiency.
As greater restrictions are being placed on industrial and municipal plants, filtration systems are being pushed to greater operating levels. The Schreiber Fuzzy Filter has enjoyed a distinct advantage over conventional media and disc-type filters by virtue of its ability to operate at over five times conventional flux rates while maintaining greater effluent quality than those technologies. The Fuzzy Filter can effectively remove suspended solids down to 4 microns, which exceeds typical media filter performance.
Schreiber’s GRO and GR systems are very versatile, and that versatility provides often-overlooked benefits for existing plants. The GRO can function as an aeration basin or an aerobic digester. The GR is even more flexible, as it can be set up for aeration/clarification or for combinations of digester/thickener/clarifier. For example, with a dual GR system, one GR can be used as an aeration/clarification unit, while the other can be used as a digester/thickener unit; the thickener can be easily converted to function as a clarifier at any time.
The continuously sequencing reactor (CSR) is a process modification of a continuous-flow, complete-mix activated sludge system. With the CSR, air is operated intermittently to allow the reactor to sequence through aerobic (oxic), anoxic and anaerobic phases, thus accomplishing biological nutrient removal (BNR) in a single reactor. Because aeration is not allowed during the anoxic and anaerobic phases, the key requirement for such a cyclical operation is that the reactor mixing must be independent of the aeration (i.e., separation of aeration and mixing).
When the Clayton County, Ga., Water Reclamation Facility (WRF) expanded its capacity from 6 million gal per day (mgd) to 10 mgd, an expansion of the filter basin was a major part of the project. This filter basin performs the plant’s tertiary filter treatment, just ahead of the ultraviolet treatment, and is made up of Schreiber’s Fuzzy Filters, which were selected in 2000 to replace the sand filters previously in place.
Schreiber often encounters questions regarding how its continuously sequencing reactor (CSR) compares to the various sequencing batch reactors (SBR) that are on the market.
Of course, the two systems are similar in that they are both activated sludge processes that produce the oxic, anoxic and anaerobic process phases over time in the same basin. However, there are some very significant and distinctive differences between the two concepts.
When you live in a desert, you learn to appreciate water. That is especially true for Lake Havasu City, Ariz. Located on the banks of 19,000-acre Lake Havasu and near the Colorado River, the city relies on the lake as an attraction for tens of thousands of tourists each year. On certain weekends and holidays, the city’s population can swell from 55,000 to more than 200,000.
Aside from the lake and river, however, water resources are scarce. The area gets only 6 in. of rain annually and has an average daily high temperature of 100°F or more for about half of the year.